1. Field of the Invention
The present invention relates to optical cavity mode mismatch sensors and, more particularly, to a mode matching sensor telescope.
2. Description of the Related Art
Higher order mode-sensing techniques currently utilize CCD cameras, clipped photodiode arrays or bullseye photodiodes. These sensors provide feedback error signals for correcting either the beam waist size or waist location, but also have drawbacks. Some of the drawbacks include slow signal acquisition for CCD sensors, 50 percent reduction in sensing capabilities for clipped arrays, and expensive custom parts that are difficult to setup for bullseye photodiodes. For example, because a clipped photodiode array requires a split in the power between the diodes, sensing capabilities are reduced by 50 percent. Similarly, while bullseye photodiodes offer a very convenient geometry to sense Laguerre-Gauss (LG) modes, they are not very commonly manufactured, difficult to setup and thus not very cost effective.